Transformer



C. H. THORDARSON,

TRANSFORMER. APPLICATION FILED APR. 23,1917.

Patented Oct. 7,1919.

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CHESTER H. THORDARSON, OF CHICAGO, ILLINOIS.

- TRANSFORMER.

Specification of Letters Patent.

Patented Oct. 7, 1919.

Original application filed September 27, 1915, Serial No. 52,775. Divided and this application filed April 23,

' 1917. Serial No. 163,865.

To all whom it may concern:

Be it known that I, CHESTER H. THORDAR- SON, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Transformers; and I do hereby declare that'the following is a clear, full, and exact description thereof, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in electrical transformers, and refers more particularly to' means designed to protect the low tension winding of the transformer against excessive loads due to surges on the high tension winding, and to means for balancing, testing or ratio transformers.

In accordance with my invention I propose to connect the coils of the low tension winding with the low tension current source, and to a grounded or other tap-off conductor, in such manner as to prevent destructive stresses being set up in the low tension winding, due to excessive surges thrown on or in the high tension winding, and to provide an efiicient electrostatic shield between the high and low tension winding. Further the arrangement of the low and high tension winding is such that in a ratio transformer, the voltage of the high tension winding is maintained straight and the low and high tension windings are automatically balanced.

In the drawings Figure 1 is a diagrammatic view of the high and low tension windings of a transformer showing my improvement applied thereto.

Fig. 2 is a detail showing the manner of connecting the ground tap-off or circuit conductor to the outer sides ofthe low tension winding coils.

Figs. 3, 4 and5 are diagrams illustrating variations of low tension winding circuits.

As shown in drawing, 10 designates the high tension winding and 11 the low tension winding of a transformer. 12 indicates the core and 13 diagrammatically indicates the insulation between the transformer windings.

In the type of transformer shown in Fig. 1 the high tension winding may be made up of a series of disklike units 18, and the low tension winding may be made up of a series of like units 19. Said units may be formed, connected and insulated in a manner generally similar to the transformer construction shown in my prior application for U. S. Letters Patent Serial No. 39,044, filed on the 10th day of July, 1915, now Patent 1,288,750, Dec. 24, 1918. It will be understood that in the diagrammatic illustration of the high tension units in Fig. 1 merely the upper cross sections of the coils or units are shown, and that in the assembled structure the high tension winding coils surround the low tension winding and the core.

First referring to Fig. 1 it will be noted that the coils or winding units 19 of the low tension winding are connected in pairs in multiple between the circuit wires 40, 41 of the low tension circuit. All the connections of the circuit wires to said coils are at their inner ends, and in the flat wire slab form of winding unit shown in my aforesaid prior application, said connections occur at the inner sides of the ringlike slab units. 42

designates a grounded conductor that is connected to the outer sides of the low tension winding coils or units 19, the connection of said grounded conductor to the said low tension winding coils being at the parts of said coils nearest adjacent to the high ten sion winding. In this manner unusual stresses set up in the low tension winding are readily distributed so as not to produce destructive stresses in any part of the winding.

A means of practically connecting the outside turns of the coils or winding units to the grounded or other conductor 42 is shown in Fig. 2 where the conductor 45 has the form of a flat bar to which are soldered or otherwise secured the outer terminals 44 of said coils, adjacent coils being reversely wound as indicated in Fig. 4.

The arrangement shown between the outer turns of the coils 19 and their terminals and the conductor 42 provides between the high and low tension windings an electrostatic shield which protects the low tension winding from electrostatic stresses developed in the high tension winding. Said shield is, in effect, a skeleton shield, being divided into a large number of sections by reason of the independent connections of the terminals of the several coils or units with the conductor 42, as indicated in Fig. 2.

In Fig. 3 is indicated a multiple series connection of the low tension winding coils or units with the low tension circuit and also the connection of the coils in groups of any desired number to the grounded conductor 42.

In Fig. 4 one of the low tension winding circuit wires 46, 47 is grounded to constitute the grounded conductor whereby the complete wiring is effected by two conductors.

In Fig. 5 is shown a similar two-wire arrangement wherein the coils 19 are connected in series in multiple between the wires of the low tension and grounded circuit.

An advantage of the construction and arrangement herein shown, wherein the disklike units or coils of the high tension winding surround or are superposed upon the low tension winding, and with the coils or units of the low tension winding connected in multiple or multiple series, as shown, to the source of exciting current, is that each group of the low tension winding automatically regulates itself to the conditions of the high tension winding so that the voltage line of the hi h tension winding is maintained straight t roughout the length of the winding. Where the low tension winding is a single coil, or is connected in series with the exciting current source, the end coils of the hi h tension winding do not respond to the in uence of the low tension winding uniformly with the intermediate or central coils or units of the high tension winding, so that l with testing or ratio transformers, inasmuch as it can be assured that a test of one or more of the coils of the high tension winding will indicate the voltage of all of the sections or units of the winding.

In all the constructions shown the common principle of providing at the outer sides of the coils of the low tension winding and between the same and the high tension winding a divided or skelton electrostatic rounded shield is maintained and also the division of the low tension winding into sections by the connection of the coils thereof in multiple or series multiple with the low tension Winding circuit.

The present application is a division of my prior application for U. S. Letters Patent Serial No. 52775, filed on the 27th day of September, 1915, now patent 1,267,013, May

I claim as my invention 2-- 1. A transformer comprising a core, a high tension winding, 2. divided low tension winding and a skeleton electro-static shield between the high and low tension windings at to the outermost turns of said units adjacent to the high tension winding.

4. A transformer comprising a core, high and low tension windings, the low tension winding comprising a plurality of units connected at their inner sides in multiple with the low tension circuit and a grounded conductor connected to the outermost turns of said units adjacent to the high tension windg A transformer comprising a core, high and low tension windings, the low tension Winding comprising a plurality of units con nected at their inner sides in series multiple with the low tension circuit and a grounded conductor connected to the outer sides of said units adjacent to the high tension windin A transformer comprising a core, high and low tension windings, the low tension winding composed of a series of connected spirally wound slab units connected to the low tension circuit and a grounded conductor connected to the outer sides of said units adjacent to the high tension wind 7. A transformer comprising a core, h i glx and low tension windings, the low tension Winding composed of a series of reversely wound units connected to the low tension circuits, and a conductor extendin across the outer sides of said units with t eouter turns of the units connected thereto. 106

8. A transformer comprising a core, high and low tension windings, the low tension winding composed of a series of connected' units made of spirally wound flat wire with the turns thereof insulated from each other 110 and a grounded conductor extendin across and connected to the outer turns of said units adjacent tow the high tension winding.

9. An electromagnetic device comprisin a core, high and low tension windings and 116 a skeleton grounded electrostatic shield between the high and low tension windin connected at intervals to the turns of t e low tension winding at the outer side of the low-tension winding.

10. An electromagnetic device comprising a core, high and low tension windings thereon, insulated from each other, and a grounded conductor connected at intervals' 'across the turns of the low tension winding adj a- 125 cent to the high tension winding in a manner to provide a skeleton grounded shield between the windings.

11. An electrical transformer comprising a core, high and low tension winding lurrounding the same, the low tension winding consisting of a plurality of units each composed of a spirally wound fiat wire with an insulating medium between the turns there- 5 of, said units being connected at their centers in multiple with the loW tension circuit, and a conductor extending across and connected to the outsides of the low tension winding adjacent to the high tension wind- 10 ing and to a grounded conductor.

12. A low tension winding for a transformer construction composed of a series of spirally Wound units in circuit with the low tension current source, a conductor extending across the outer sides of said units, and 15 the outer turns of the units being connected thereto reversely from opposite sides thereof.

Signed at Chicago, Illinois. this 1st day of March, 1917.

CHESTER H. THORDARSON.

Witnesses:

W. L. HALL, A. E. WALBIDGE. 

